Regeneration of catalysts



Patented Nov. 17, 1931 UNITED STATES PATENT OFFICE ALFRED JOSEPH, OFENGHIEN,

FRANCE, ASSIGNOR TO COMPAGNIE INTERNATIONALE POUR LA FABRICATION DESESSENCES ET PETBDLES, F PARIS, FRANCE, A LIMITED JOINT-STOCK COMPANY OFFRANCE REGENERATION or cATALYsTs No Drawing. Application filed July 11,192$}, Serial No. 377,623, and in France July 13, 1928. i

This invention relates to a method of regenerating catalyzing agents inthe treatment of carbonaceous substances or heavy hydrocarbonstor theconversion thereof into light hydrocarbons.

Catalyzing agents such as metals, metallic oxides, mixtures of metals oralloys, are usually employed for promoting reactions, and particularlfor causing the fixation of hydrogen on ydrocarbon gases, derived eitherfrom the distillation of combustibles (lignites, shales, peats and thelike) or from the distillation or cracking of tars, heavy oils or othersimilar starting materials. Such catalyzing agents, at the end of a moreor less long period, variable according to their nature and the natureof the starting materials, become coated and sulphided, particularly incracking operations wherein they become entirely charged with sulphurand carbon. It then becomes imperative to proceed with the regenerationthereof.

For this purpose, various means tending generally to eliminate thesulphur either-by the action of hydrogen or of a gas containmg hydrogen,or by the action of a stream of air, and to eliminate the carbon by theaction of a stream of air or oxygen giving rise to the formation ofcarbon dioxide or carbon monoxide or a mixture of these gases, have beenproposed.

The subject of the present invention is a method of regeneration whichenables these known means to be utilized in a far more effective manner.This method consists, in principle, in bringing into contact with thecontaminated catalysts, a mixture of air or oxygen and steam, byadmitting such mixture, by a nozzle into the reaction chamber containingthe catalyst to be regenerated. The dissociation of the steam gives riseto the formation of nascent oxygen and hydrogen. The oxygen thus set.free adds itself to that of the injected air for aiding the latter toburn the carbon and sulphur, and produce, according to temperature. COor CO or a mixture of these two gases and a slight amount of $0 The airis injected in a suitably regulated amount for ensuring progressivecombustion.

As. regards the nascent hydrogen, this reduces the formed S0 to thestate of H S, and likewise reduces the metallic sulphide, beyond theinitial zone Where the combustion of the carbon has just been produced.Subsequently, when the oxygen has been brought to act beyond the initialzone, it will find itself only in the presence of a very slight quantityof sulphur. It has been determined that at the outlet end of theapparatus there issues practically as a sulphur compound, only H S. Bythis, the oxygen is therefore in the major part employed in thecombustion of carbon, and not in the combustion of the sulphur, whichpresents the important advantage of rendering impossible the formationof sulphates, in thus enabling a complete regeneration of the catalyzingagents.

The employment alone of steam or of air, which means have already beenpracticed, would be unadapted to furnish the same results. i

By the employment of steam alone the desired amount of oxygen is notfurnished to effect, by the combustion of the carbon, the elevation oftemperature necessary for the dissociation of the steam; a considerablead" dition of heat is required, which represents a serious expense whichthe new method avoids. By employment of air alone, such add tion of heatis avoided, but, on the other hand, the reverse disadvantage isencountered of an excessive generation of heat, pre udicial to thepreservation of the catalyzmg agents.

In carrying out regeneration in accordance with the invention, two ormore catalytic reaction chambers may be mounted in parallel, one beingin service when, in the'other or others, cut out of circuit,regeneration is,being effected by a mixture of steam and air or oxygen,and vice versa. The alterations of placing in circuit for the operativereactions and out of circuit with a view to regeneration may be effectedby employing an arrangement for cyclic permutation which forms thesubject of French Patent No. 654%2, filed the 6th October, 1927.

As a modification, to the gases on the ad-= mission thereof into thereaction chambers, may be added the mixture in suitable proportions ofsteam and air or oxygen, the regeneration being effected in such caseimmedi- 5 ately after the reaction and without puttin the reactionchambers periodically out o circuit.

Claims:

1. The method of regenerating catalysts used in the treatment ofcarbonaceous substances which consists of removing the carbon andsulphur impurities by subjecting the contaminated catalyst to thesimultaneous action I l of steam and air.

2. The method of regenerating catalysts used in the treatment ofcarbonaceous substances which consists in removing the carbon andsulphur impurities by subjecting the catalyst to a mixture of steam andoxygen.

3. The method of regenerating catalysts used in the treatment ofcarbonaceous substances which consists in removing the carbon andsulphur impurities by subjecting the catalyst to a stream of steamenriched with air.

4. The method of regenerating catalysts used in the conversion of heavyhydrocarbons into light hydrocarbons which consists in the removal ofcarbon and sulphur by subjecting the catalyst to the s multaneous actionof oxygen and steam, the supply of oxygen being controlled to preventthe development of excessive temperatures and reduction of the catalyst.

5. The method of regenerating catalysts which consists in removing thecarbon and sulphur impurities therefrom by injecting, through a nozzle.into the chamber containing the contaminated catalyst a gaseous mixturecontain ng steam and oxygen.

' In testimony whereof I have signed this i specification.

ALFRED JOSEPH.

